Antistick coating material



Patented Apr. 18, 1933 UNITED STATES PATENT JAMES HOWARD YOUNG, FPITTSBURGH, PENNSYLVANTA ASSTG-NOR TO H. H. ROBERTSON COMPANY, OFPITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA No Drawing.

This invention relates to antistick material for coating sticky surfacesand particularly surfaces of asphalt, bitumen and like materials, andhas for its object to provide a superior antistick coating material,which does not discolor on standing for material lengths of time, whichdoes not peel off, which does not decompose readily and therefore can bemade up in relatively large quan- 1 tities and kept in stock, which isinexpensive and is more fire-resisting than antistick materials now inuse and known to me.

To this end, the improved antistick coating is provided with a basecomposed of a salt or salts of alginic acid, with which is incorporateda material for reducing the surface tension of said base.

By employing an alginate as the base of the antistick material, anantistick material may be produced with certain alginates, which issoluble in water and remains soluble, whereas with certain othermaterials the soluble antistick material may be converted into aninsoluble antistick.

The solution of alginate in water if applied to an asphaltic or likesurface in a relatively thin film does not possess a sufliciently low'surface tension to enable it to be used alone as it would gather inglobules and leave portions of the asphalt uncovered, and therefore thesolution of alginate has added to it a relatively small quantity of soapor other material capable of reducing the surface tension of thealginate so as to allow the asphalt surface to be wet with or covered bya. thin film of the alginate, which, when dried, forms an effectiveantistick coating, Which enables metal sheets, bars and like articlescoated with asphalt to be packed together and shipped without stickingtogether.

A solution of alginate and soap or like tension reducer may be usedalone, but it is preferred to employ therewith a small amount ofglycerine or other material capable of imparting flexibility to theantistick coating ANTISTIGK COATING- MATERIAL Application: filed March19, 1929. Serial No. 343,358.

and a small amount of glue or like material capable of impartingglossto'the antistick coating when dried on the asphaltic or like stickysurface.

An eflicientantistick solution may be made with the followingproportions, to wit:

I Per cent- Alginate e 2 Soap 1 Glycerine 1 Glue 4' of 1 The alginatesused may be single salts, such as sodium, potassium or ammoniumalginates,'or double salts, such as copper ammonium alginate or zincammonium alginate.

The'antistick material made with any of the above materials isfsolublein water. and when applied'to'a'n asphaltic or bituminous or like stickysurface vwets and covers the same and when dried forms an effective andinexpensive antistick coating, which is solu ble in water and can bewashed off with water. I 1 I On the other hand, an antistick alginatecoating which is wholly or partially insoluble in watenmay be obtainedby treating the soluble antistick 'materialwith acid solutions orwith'solutions of salts capable of converting the soluble'antistick intoan insoluble antistick.

Calcium chloride, magnesium sulphate and the like may be used for thispurpose.

The double salts of copper ammonium alginate or zinc ammonium alg'inateare initially soluble in water but when dried and heated as on exposureto the sun tend to become less soluble.

In United States Patent No. 1,327,933 granted to me January 13, 1920, isdescribed 35 a soluble antistick material employing a cellulosic base,and while such antistick is efficient for preventing asphaltic,bituminous, or like surfaces sticking together when shipped or packed,it possesses. certain objec- 9 tionable characteristics, to wit: itdecomposes rapidly which prevents its being made up in relatively largequantities and kept in stock. It discolors on standing and is liable topeel off when applied to the asphaltic or like sticky surface.

It is more expensive and having a cellulosic base is less resistant tofire.

The improved antistick having an alginate as itsbase does not. havetheobjectionable characteristics mentioned.

What is claimed is:

1. An antistick coating material, comprising an alginate base, soap,glycerine, and glue substantially in the proportions specified.

2. An antistick coating material for sticky surfaces, comprising a metalalginate base initially soluble in water and having a relatively highsurface tension in water solution, and a soap incorporated therewith forreducing the surface tension of the water-dissolved material forproducing a non-sticky layer which adheres firmly to the sticky surface.

3. An antistick coating-material for sticky surfaces, comprising adouble metal alginate base initially soluble in water and having arelatively high surface tension in water solution, and a soapincorporated therewith for reducing'the surface tension "of thewaterdissolved material for "producing a non-sticky lfayer which adheresfirmly to the sticky surace.

4. An antistick coating material for sticky surfaces, comprising as abase a double alginate of ammonium and a metal, which is initiallysoluble in water and has a relatively high surface tension in watersolution, and a soap incorporated therewith for reducing the surfacetension of the water-dissolved material for producing a non-sticky layerwhich adheres firmly tothe sticky surface.

5. An antistick coating material for sticky surfaces, comprising a metalalginate base initially soluble in water and having a relatively highsurface tension in water solution, a soap incorporated therewith forreducing the surface tension of the water-dissolved material forproducing a non-sticky layer which adheres firmly to the sticky surface,and an agent reactive with the base for converting the alginate toinsoluble form.

In testimony whereof, I have signed my name to this specification.

JAMES HOWARD. YOUNG.

